In this article we explore the extent of the digital connectivity and character of the mediated solidarity discernible between a selection of militant antifascist groups in the USA and UK on Twitter. By studying the geographical scalarity of the retweet practices of six case study groups in these two countries (from New York City, Philadelphia, Portland, Brighton, Liverpool, and London) and the content of a sub-sample of these groups’ retweets we highlight that their Twitter connectivity is relatively limited. We also suggest that the sorts of mediated solidarity, or as we specifically refer to it here ‘retweet solidarity’, that this connectivity reflects is rather shallow. As such the article’s broader contributions relate to firstly the need for studies of digital connectivity within social movements that do not preemptively assume that translocal or transnational activism is an automatic by-product of social media use, and secondly the necessity to continue problematizing the idea of solidarity in digital contexts.